There are numerous situations where hand washing or cleansing is particularly important, such as in hospitals, food preparation areas and public toilets. Statistics show that people in general do not wash their hands as often as needed or to the degree needed for effective infection control. Therefore it would be useful to be able to monitor the observance of hand washing requirements.
The preparation, handling and cooking of food in establishments such as restaurants requires very high levels of hygiene and cleanliness. Contamination of food is recognized to happen primarily through contact with workers hands, other food stuffs and/or surfaces that are contaminated. Contamination can lead to infection of diners including serious illness with life changing consequences and even death in the most serious of outbreaks. Furthermore, the reputational damage to a business of an outbreak of illness caused by contaminated food may be so considerable as to result in closure of the business. In any event, significant litigation and compensation costs may fall on insurers causing insurance premiums to rise significantly.
The food preparation environment is often pressured, busy and cramped with staff members varying greatly in experience and competence. In addition, many restaurant workers are young, low paid and inexperienced with these factors being further exacerbated by high rates of turnover of staff and the use of casual workers.
Staff working in kitchens for food preparation and cooking are, in many countries, required to comply with legal regulations on food handling and hygiene including hand washing. For example, such regulations are issued by the Food and Drug Administration (FDA) department in the USA and the Foods Standards Agency (FSA) in the UK. In many cases, such regulations require the provision of sinks or wash basins dedicated only to hand washing for which soap is mandated in order to achieve an acceptable quality of hand washing followed by drying with single-use paper towels. Hand sanitizers are not efficacious for many contaminants that may be transferred by hands to food and so are often not sanctioned in food preparation environments.
It is generally accepted in the food preparation industry worldwide that hand washing performance by relevant staff is much too low, but businesses find it very difficult to measure it effectively and economically, to increase its occurrence among staff, and to verify changes and then sustain them. A significant challenge is to measure hand washing frequency and the quality of the washing process. This is difficult by manual direct observation due to the complex environments in which observation is required and impractical to do continuously. At present, the risk is often managed largely through insurance in case an infection is caused, but this of course does little or nothing to mitigate the risk to a business's reputation from an outbreak caused by contamination of customers' food. If a restaurant could demonstrate acceptable hand wash compliance to certain sustainable standards, insurance companies might offer a discount on premiums in recognition of the reduced risk of food illness outbreaks resulting from improved, sustained hand hygiene practices.
In other environments, such as hospitals at the point of care delivery, there are areas that are considered clean such as the zone around a patient where portal sensors may be used to determine when healthcare workers enter and leave the “patient zone.” This is however not analogous to food preparation environments where staff involved in food preparation may remain at a location for long periods without coming and going over a positional threshold. Similarly, in the same area other workers including managers and servers such as waiting staff may pass through without having the same requirements to wash their hands.
Methods of monitoring and attempting to improve frequency of hand hygiene used in the past include:                1. Manual surveys and audits combined with feedback and/or training. Direct observation by human auditors has been shown to give rise to the “Hawthorn effect” where performance is improved above normal levels because staff know that they are being observed. Training can improve performance temporarily but this is typically not sustained without continued intervention. Remedial training and prompting may typically be required frequently especially where there are high levels of staff turn-over and low paid or young workers are involved who are poorly motivated.        2. Monitoring every interaction of an individual with soap dispensers or sinks has been tried however this requires technology of the type such as RFID tags on employees which have been found to be problematic in that they cause resentment and are not liked. Additionally, they incur a management overhead especially if staff turn-over is frequent and significant. A further disadvantage of tags is that they may be forgotten, lost, accidentally damaged or sabotaged rendering the system unable to properly monitor individuals. Further, wireless tags on employees typically must interact with a sensor at the sink, usually on the soap dispenser or tap/faucet. Installing a tap sensor typically involves introduction of an electronic sensor to the plumbing and is not preferred. Finally, even if reliable, where the only indication of a wash is that the soap dispenser was operated, a disadvantage is that it may be carried out without washing to give a false view of a worker's hand hygiene performance and easily render the data non-representative.        
As demonstrated in many industries, in order to improve a process or performance it is often preferrable to identify a meaningful metric that is indicative of performance and to have a reliable and accurate means to measure it. There is no universally accepted and monitored metric identified for the food industry with respect to hand washing. However a useful metric is the number of hand washes per relevant employee per period of time. The technical challenge therefore is to measure this accurately starting with measurement of hand washes meeting an acceptable standard.
Automatically measuring the quality of a hand wash is technically complex and normally cannot be satisfactorily achieved by an automatic system. Instead, it typically requires a trained human observer who must visually, e.g., manually, determine the extent to which all the steps of the recommended procedure are carried out, such as the World Heath Organisation's recommended hand washing procedure.
US2009/0087028A attempts to address this problem. It discloses that the recommended time for hand washing is a minimum of 15 seconds of hand rubbing and that studies have shown that both long (3 mins) and short (10 seconds) wash cycles can produce a ten fold reduction in the median number of transient bacteria thereby suggesting that hand washing technique is much more important than duration. Consequently, US2009/0087028A proposes an automatic hand washing monitoring system comprising a camera and a processor, the processor being adapted to receive from the camera images of hand washing activity. The processor analyzes mutual motion of hands to determine if the hands mutually move in desired poses, and if so, the durations of the patterns; and, in response, generates a hand washing quality indication according to the analysis. This is a computationally very intensive and difficult monitoring process to implement requiring a high resolution camera. Furthermore, as a very exacting hand washing technique is required to achieve a hand wash of sufficient quality to be considered a pass, this monitoring system necessitates a significant amount of staff training. Also, depending on its implementation, this monitoring system can lead to excessively long hand washes which staff may not like and are therefore not motivated to implement on a sustained basis.